Not to be a real downer or anything but I just don't see the OP wanting an informed response. First he hasn't come back since he said he wanted to go to the Nvidia forums, second his first response was frankly a little bit on edge as the question of why is a legitimate question and can make a difference in what to recommend. If the OP is still around, you need to provide us with other information such as what you are planning on doing with said system. As others have said resolution plays a part as well as does every other component. If you stayed around and ask and answer politely you will find a huge resource of knowledge here. Then again I think we are only talking among ourselves now.

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"Nothing sucks more than that moment during an argument when you realize you're wrong."

4 GTX 580 would have more power, but also you need to consider that having 4 cards in the system they will overheat a lot more than just two. They will basically take the hot air from each backplate with the exception of the lowest one which will have the freshest air. I made an arrangement with 3 cards like this and adding one on the second slot between 1st and 3rd, raised the GPU temperature of the card in first slot by 10 degrees Celsius, forcing me to modify the fan profile in order to keep it silent. This is done, despite having a lateral fan blowing fresh air inside the case, So there are these considerations to take in the account too. in this light 2 x 590 would make more sense, and the cards will breath better and be quieter too.

Sorry, I disagree with some here, you'll get better overall performance from 2 x 590's in Quad SLi then 4 individual Cards, nv simply hasn't bothered to optimize Drivers for 4 Cards yet, likely never will, yes some performance boost with the 4th Card, but minimal.
I didn't bother checking any of your choices in your poll as the once choice you left out that I would consider for a "super high Res build), as in 3 x U3011, would be a more simply Tri SLi 580 3Gb set-up. These you'll be able to OC quite high, scaling will be a ton better than Quad SLi, power consumption will be reasonable (1 good 1.2kW PSU) and your results will be very good as far as gaming goes.

Give me some proof if I'm wrong, but 2x 590 uses 4-way SLI, so therefore using 4 faster clocked GPUs will provide you with more speed than 4 slower. I have a friend with 2 x GTX 295 and he either enables 4-way SLI or 3-way + 1 dedicated physX. I will also say that the OP should consider your point about 4-way SLI support as most games will see no benefit from the 4th card.

Give me some proof if I'm wrong, but 2x 590 uses 4-way SLI, so therefore using 4 faster clocked GPUs will provide you with more speed than 4 slower. I have a friend with 2 x GTX 295 and he either enables 4-way SLI or 3-way + 1 dedicated physX. I will also say that the OP should consider your point about 4-way SLI support as most games will see no benefit from the 4th card.

There is probably less overall latency though with 2X 590s vs 4 X 580s though. As well as Lane restrictions on anything short of a X79 board.

Give me some proof if I'm wrong, but 2x 590 uses 4-way SLI, so therefore using 4 faster clocked GPUs will provide you with more speed than 4 slower. I have a friend with 2 x GTX 295 and he either enables 4-way SLI or 3-way + 1 dedicated physX. I will also say that the OP should consider your point about 4-way SLI support as most games will see no benefit from the 4th card.